Isn't Instagram basically similar now to the original FB product during its best years?

My social circle (consisting mostly of people in their upper 20s to early 40s) has largely abandoned FB in favor of Instagram. My understanding is the younger age brackets are also falling off Instagram in favor of things like Snap and TikTok? (correct me if wrong).

Seems like the major users of the original FB product are now older and/or less tech-saavy people who were late to catch the social networking boat? Again, correct me if I'm wrong.